In the manufacture of rings of various types, strip stock is fed through a forming mill to impart to the ring stock the desired sectional shape. The stock then passes through a bender which then coils the stock into a ring or helix condition. In order to sever the stock of the desired size with any degree of accuracy, flying cutoffs are usually employed.
Flying cutoffs are well known in the art and the dies thereof are accelerated to the speed of the work in order to make the cut. After the cut is made the dies are stopped and returned to the original position to make the next cut. Flying cutoffs require complex controls and also require a great amount of energy, particularly if the cutoff is of any size, to accelerate the dies, make the cut, stop the dies, and then return them to the original position. Moreover, when forming rings, the cutoff and die may require to travel in a circular path, further complicating the drives involved.
With flying cutoffs the cycle of operation is normally lengthened to permit the acceleration, the cut, the stop, and return of the original position. Accordingly, flying cutoffs limit the productivity of the ring forming machine.